a. fX174 Data were collected on fX174 procapsid crystals. Frozen native and heavy atom derivative crystals diffracted to 6 _ resolution. The resultant data provided the breakthrough for the structure determination. Warm crystals diffract to at least 3.5 _ resolution. We anticipate a full structure determination by later this summer. Currently, phase extension (now having switched to the higher resolution warm data) extends to 5.4 _. The D scaffolding protein is seen to be exceedingly helical in its secondary structure. The F, G and J structural proteins compare well with the earlier determination of the infectious virion. This is perhaps the first example of a chaperone complexed with a substrate. b. Picornaviruses It has been possible to freeze HRV14 crystals with resolution at least as good as the warm data. The quality of the data is much superior. Native and HRV14:antiviral agent complex data were collected. c. Parvoviruses A partial data set of the first insect parvovirus (of wax moth) has been collected. The crystals were frozen. Insect (denso) viruses have little, if any, homology to the earlier work on mammalian parvoviruses. Data on mouse parvovirus were collected at CHESS and the structure was solved. d. HIV capsid A number of data sets of HIV-CA (p24) complexed with a bound Fab fragment were collected on the F2 station. A Pt derivative and a Se-Met CA protein were used for MAD data collection. Unfortunately, the Pt was not well substituted and there was a lot of wavelength drift while collecting the Se data. The latter are still being analyzed. e. Alphaviruses All crystals of Ross River virus were of insufficient quality to give useful diffraction.